In an interview scheduled to air in Nevada tonight, Sen. John McCain (R-Ariz.) took aim at the state's senior Senator and his claim about presumptive GOP presidential nominee Mitt Romney's tax returns.

McCain disputed Senate Majority Leader Harry Reid's (D) contention, based on information from an unnamed source, that Romney did not pay taxes for a decade.

"I think he is wrong," McCain said about Reid before acknowledging that he did not personally look at all of Romney's returns.

McCain campaign aides reportedly reviewed 23 years of the former Massachusetts governor's tax returns as part of the vetting process when McCain was choosing his vice presidential running mate in 2008.

"I am absolutely confident" that Romney did pay taxes during those years, McCain added.

Some Democrats have suggested that McCain passed over Romney in favor of then-Alaska Gov. Sarah Palin because of issues with Romney's paperwork. In the interview, recorded Monday, McCain again insisted that is simply not true.

"The reason why I picked Sarah Palin is because I thought she was the best candidate at the time," McCain said.

Reid's unsubstantiated claim has drawn significant ridicule. He has said that a source connected to Romney's former company, Bain Capital, informed him that Romney did not pay taxes for 10 years.

"Let him prove he has paid taxes, because he hasn't," Reid said on the Senate floor before the August recess.

Republican Sens. Lindsey Graham (S.C.) and Kelly Ayotte (N.H.) joined McCain for the sit-down interview with Las Vegas political columnist Jon Ralston, which is scheduled to air in full tonight on his local television program "Face to Face."

The three Republican Senators were in North Las Vegas to discuss the potential impact of mandatory budget cuts to the military.

Graham did not mince words.

"Harry's making it up. He's making this up!" Graham said. "He's trying to interject himself in the presidential campaign using the floor of the Senate in a way no one else has done in the history of the Senate."